While heat development, for example of a high-economy, performance-optimized diesel engine, can be very low on the cylinder crankshaft housing, this low heat development in no way applies to “hot zones” such as manifolds, turbochargers, catalytic converters, etc. Due to the more and more compact construction of engines, components which are not thermally “compatible” are increasingly being placed in close proximity to one another. Accordingly, heat-sensitive assemblies, such as sensors, fuel lines, pressure cells, body parts, etc., must be protected against adjacent thermal engine components. The situation is exacerbated by the compact structure in that the high packing density of the assemblies constricts the cooling air flow in the engine compartment. Noise abatement measures can also contribute to this high packing density. Thus, for example, plastic bottom plates, designed to reduce the emission of noise from the engine compartment to the roadway, under certain circumstances can produce effective insulation with which heat is enclosed in the engine compartment. Catalytic converters, due to their phased high surface temperature, are considered to be among the heat sources which certainly may necessitate the use of protective shield barriers. One typical example of this need is design measures such as positioning the catalytic converter close by the manifold. This design principle, which performs the function of rapid heat-up of the catalytic converter reducing emissions in the cold start phase, shifts a major source of heat into the engine compartment where numerous assemblies are crowded in a tight space. One reason for the growing importance of shielding components, such as heat shields, is the trend toward use of thermoplastics. The light and economical materials with their exceptional moldability are rapidly becoming common in the engine compartment, but require special attention with respect to ambient temperatures at the application site relative to other thermal engine parts (“New materials and development tools for heat protection”, in MTZ 12/2001, Vol. 72, pp. 1044 ff).
DE 102 47 641 B3 discloses a structural component in the form of a noise-damping shielding component, as a component of a motor vehicle. To improve acoustic insulation, this shielding component has shield components which are made flat, which lie at least partially on top of one another, which accommodate an insulating intermediate layer between themselves, and which are joined to one another on the outer circumferential side along a common connecting line for secure connection to one another. The joining is by one shielding component with overlap of the insulating intermediate layer encompassing the other shielding component in the same overlap in the manner of flanging. This known positive-locking connection fixes the individual layers or shield components immovably relative to one another. As a result, the produced connection is rigid. In this way, especially in thermal expansion processes for the shielding component, problems arise in fixing it, especially when, as in the indicated known solution, the shielding component is fixed within the engine compartment on its stationary parts by angular bracket legs which act on the edge side. Possible warping of the multilayer shielding component with potential bulging and tearing of the heat shield material can occur, which can lead to failure of the shielding component. The angular bracket legs as fixing means can become detached from the engine components by the provided screw connection. In this way, the shielding component can be released requiring the corresponding repair and maintenance. The known solution is also expensive to implement, since angular bracket legs must be provided in addition for fixing. This fixing also increases the installation cost in production lines of motor vehicles.